Matthew, just had to jump in here with a note of caution ... PLEASE do not suddenly think that because Anthony said "I have three times the BTA's you have in a tank half your size, and I do not encounter any of the issues you're having ... " that this means you are also within a "safety zone" and can get more 'nems. I've been following along your various threads because I'm interested in how your tank is doing and I (along with all the other "uncles" here) want you to be successful. Also, all the things I would have said were noted by others, so no need to beat the issue.
Having said this, I'm pretty sure that Anthony's BTA population has been achieved not by buying a bunch of anemones over a short period of a month or two and putting them together. I believe all his have split normally and the density has been acheived because the anemones are happy and are reaching a normal state of equilibrium. There is a HUGE difference between a colonly replicating naturally thorugh splitting (all the animals are genetically identical) and mixing specimens from different locations. Even though the anemones may be of the same species, the variance in sourcing (different water chemistries, light levels, currents, natural food sources, etc.) may cause them to conflict with each other. I have noticed that occasionally some of my BTAs (ones from different sources) will retract their tentacles when touching another BTA, and over time will possibly drop some tentacles or have them shorten to stubs. This doesn't always happen, but if I do not provide enough space for an anemone to seek out a spot with conditions it likes and open fully without touching another one, then I am not being a responsible aquarist.
Remember that happy anemones (esp. BTAs) find a single spot, stay there, and open fully. Those that are not happy will not open fully and will often move about since this is their way of trying to find a spot that is good for them.
With respect to your situation, please do try the carbon and make sure that with it or any particulate additive you place it in a mesh bag or other suitable container and wash, wash, wash. You should never get a major color change in the water or cloudiness when adding these items if they have been properly and very thoroughly washed first.
Also, and I hope I don't tread into the area of being too invasive in telling you how to manage your tank ... I would really highly recommend you look deeply into yourself and objectively consider whether you have way too many anemones in your tank right now. Sure it may look cool to have a wall of anemones, but that should be achieved naturally over a period of time like in Anthony's case, not by buying a couple anemones (and extremely large ones at that) and honestly overloading the tank. Remember the magic line that was mentioned earlier ... each system has an attainable bioload that defines what it can naturally hold (you may have heard the 1" of fish per gallon rule for FW...). The problem with SW unlike FW is that we have access to a huge host of invertebrates that also add to the bioload because they respirate just like fish. And as Norm mentioned, when we buy something on a rock, we don't think about all those things inside the rock (sponges, worms, etc.) that also add to the bioload. Therefore, it can be very deceiving as to how loaded your tank may really be.
So, please look deep into your heart and think what is good for the animals, not what you want to do with respect to loading up the tank. Remember, your animals are the best guage of the health of your tank, and if they are not looking happy, something is wrong.
